1. Field of the Invention
The present invention relates to a semiconductor package and mounting socket thereof. In particular, the present invention relates to a semiconductor package and mounting socket thereof suitable for miniaturization of a semiconductor device, in which an external lead connected to an external terminal is formed in a shape of ball that is supported in a package body.
2. Description of the Prior Art
Generally, in the manufacturing process of a semiconductor device, after devices such as circuits etc. are formed in a semiconductor chip, the semiconductor chip is mounted in a lead frame and sealed in the form of a package so as to protect from external shock and damage. Then, a contact terminal is extracted from one of the sealed portions so that it can be electrically connected to an external device.
The semiconductor package has a semiconductor chip mounted on a die pad of a rectangular shape with adhesives. The package is constructed in such a way that a plurality of leads are positioned at a given distance around the die pad, contact pads of the semiconductor chip are bonded to the die pad side of the leads with wires, and the semiconductor chip, the die pad and the wires are encapsulated by a package body made of epoxy mounting compound (hereinafter called "E.M.C").
This semiconductor package is in a form where a lead is connected to the external terminal (hereinafter called "external lead"), but can be classified into various types depending on the extraction direction, the packaging, or the mounting method of a chip. A single inline package (hereinafter called "SIP") type and a dual inline package (hereinafter called "DIP") type in which external leads project from one side or both sides of the package body is mainly used in the insertion mounting type such as memory devices of DRAM or SRAM etc. in which external leads are inserted into holes. A quad flat package (hereinafter called "QFP") type such as a central processing unit etc. in which external leads project from all directions of the package body is mainly surface-mounted on a printed circuit board (hereinafter called "PCB") in which external leads are curved in the shape of a gull wing.
In addition, there are general types in which a package is mounted on a die pad and connected to leads by wires depending on the mounting method of a semiconductor chip, a chip on lead (hereinafter called "COL") type or a lead on chip (hereinafter called "LOC") type in which contact terminals of a semiconductor chip are directly connected to leads, a chip on board (hereinafter called "COB") type in which a semiconductor chip is directly mounted on a PCB, a tape automated bonding (hereinafter called "TAB") type in which conductive wires serving as leads are included etc.
FIG. 1 is a sectional view of a semiconductor package according to a prior art, which is an example of DIP type.
First, as can be seen in FIG. 1, in the semiconductor package 1, a semiconductor chip 2 is mounted on a die pad 4, and a plurality of leads 16 are extended around the die pad 4 at a given distance. Internal leads 16A being one side of the leads 16 are bonded to the semiconductor chip 2 by wires 8, and a package body 3 encapsulating the semiconductor chip 2, the die pad 4 and the wire 8 is formed with EMC. External leads 16B are projected toward both sides of the package body 3.
In a semiconductor package according to the prior art as described, since external leads vertically curved against a package body are inserted into holes of PCB and then mounted thereon, there is a high possibility that the external leads are inclined to be deformed or cut upon handling or mounting and reworking of the package; and there are problems that deteriorate contact between the external leads and the holes and reduce electrical characteristic of a semiconductor package.
Increasing mounting density and thus miniaturization of a semiconductor device is made difficult because space necessary for an insertion mounting process must be secured and design of a socket into which external leads are inserted is limited.